Sealing MDF Spoilboard Edges

Quick and effective ways to seal spoilboard edges. December 28, 2014

Question (WOODWEB Member) :
Does anyone have a good way to seal the edges of MDF for spoilboards? We are using the foil tape, but it is a pain in the neck. Is there a more effective way to seal the edges - maybe paint?

Forum Responses
(CNC Forum)
From Contributor J:
We mix wood glue with water 50/50 and seal them.

From the original questioner:
How do you apply it - brush or roller?

From Contributor J:
We use both depending on what we have at hand.

From Contributor W:
We used to run them through the bander (wood or p-lam - do not use PVC). Contributor Jís method is far better.

From contributor B:
I like to use iron-on edgebanding.

From contributor C:
We use two coats auto body primer, using strips of cardboard to protect the bed.

From contributor K:
Caulk works great.

From contributor M:
Run it through the bander without tape. Remember to back off the pressure wheels so the glue will stay on the wood.

From Contributor D:
We buy five-six sheets of standard, double refined (not ultralight) MDF and stack them in the spray booth. I spray all the edges with four-five coats of clear lacquer, sanding lightly between coats. I block off the top sheet to minimize overspray, but it doesn't really matter much because you get rid of it when you make the first pass surfacing the spoilboard. I used to edgeband the boards, but got tired of the banding chipping when we surfaced the panel. I was also amazed at how much better our vacuum pump works using this method - the gauge shows about ten more PSI than before, even when there is no sheet on the machine. The lacquer really seals the edges completely. I just used the last sheet and am about to buy another five-six sheets. These lasted me about eight months, but obviously it depends on how much you are using the router.

From the original questioner:
Thanks to all who have responded. The 50/50 glue water mix really works well for us. The spray booth idea may be something we will try in the future.